Adenia volkensii (PROTA)

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Plant Resources of Tropical Africa
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Adenia volkensii Harms

Protologue: Engl., Pflanzenw. Ost-Afrikas C: 281 (1895).
Family: Passifloraceae

Vernacular names

  • Kilyambiti plant (En).

Origin and geographic distribution

Adenia volkensii occurs in eastern Africa from Somalia south to Malawi.


In East Africa a leaf decoction is taken orally to treat bronchitis, coughs and fever, or is used as a purgative enema. Pounded seeds are given in enema form as a diuretic. A few drops of sap are sucked from a piece of twig or stem to treat gonorrhoea; larger amounts are very poisonous. Powder of the roasted rootstock is taken in Kenya to treat coughs, colds and pneumonia and with milk to treat stomach-ache and internal swellings. The rootstock is also used to cure trypanosomiasis and venereal diseases in livestock. The fruit and roots are used to poison hyenas.

Adenia volkensii is collected, grown and traded as an ornamental by enthusiasts.

Production and international trade

Leaves, rootstock and bark are sold for medicinal purposes in local markets, but Adenia volkensii is also commercially important because pharmaceutical products are produced industrially from the same plant parts.


The most important active ingredient of Adenia volkensii is volkensin, a galactose-specific lectin (glycoprotein) consisting of an A and a B subunit, linked by disulfide and noncovalent bonds. Volkensin is a potent inhibitor of eukaryotic protein synthesis in whole cells as well as in cell-free systems. The inhibitory activity is a function of the A subunit; the B subunit has a lectin function and allows the protein to pass the intact cell membrane. Volkensin is one of the most lethal double-chain ribosome-inactivating and ricin-like toxins; in rats the LD50 is 50–60 μg/kg. Chemically, it resembles most closely modeccin, the toxin of Adenia digitata (Harv.) Engl. In a rat model volkensin could be used effectively to produce anatomically selective lesions in the brain. It causes neuron death not only at the injection site, but it is also transported between neurons. Possibilities have also been studied of selectively killing mononuclear macrophages, the cells in which the HIV virus survives and which transfer it to T-cells in which the virus is rapidly multiplied resulting in the development of Aids.

All parts of Adenia volkensii, even the flowers, contain cyanogenic glycosides, with the rootstock accounting for about 90% of the amount of these compounds. The cyanogenic glycosides isolated are tetraphyllin B (barterin) and its epimer epi-tetraphyllin B (volkenin).


Usually monoecious shrub or herb up to 1.5 m tall, with annual shoots of 20–50 cm long growing from a rootstock or caudiciform, succulent stem up to 100 cm long; tendrils absent. Leaves alternate, simple; stipules 0.5–1.5 mm long, triangular, acute; petiole 1.5–10 cm long; blade entire or more or less deeply 3–7-lobed, orbicular to ovate or rhomboid in outline, 3–16 cm long, base cordate to truncate, apex acute, mucronate, margin toothed or dissected, with 2 glands at base, 2–6 glands on lower leaf surface, and blackish glands on the teeth. Inflorescence an axillary cyme, 1–6-flowered in male, 1–2(–3)-flowered in bisexual and female inflorescences; peduncle up to 0.5 cm long; bracts and bracteoles lanceolate, 2.5–10 mm long, acute, toothed and gland-dotted. Flowers usually unisexual, regular, 5-merous, glabrous, pale greenish or cream; pedicel 5–25 mm long; calyx with long tube and shorter lobes, woolly hairy at margins; petals free, corona consisting of branched hairs 1.5–3 mm long; male flowers with calyx tube 12–20 mm long, lobes ovate-triangular, 3–9 mm long, obtuse, petals lanceolate-linear, 10–14 mm long, acute, with many branched hairs 3–5 mm long at margins, stamens free, ovary rudimentary; female flowers with calyx tube 7–10 mm long, lobes oblong, 5–8 mm long, obtuse, petals linear, 8–12 mm long, with few branched hairs, ovary superior, ellipsoid, 4–8 mm long, styles connate for 2–4 mm, the arms c. 1 mm long, stigmas c. 4 mm in diameter, much-branched, woolly-papillate, stamens rudimentary. Fruit a globose to ellipsoid capsule 3.5–5.5 cm × 3–4.5 cm, leathery, 15–30-seeded. Seeds ovoid, 8–9 mm × 7–7.5 mm × 3–4 mm, pitted.

Other botanical information

Adenia comprises about 95 species, with about 60 species on the African continent, 20 in Madagascar and 15 in Asia. The genus is subdivided in 6 sections. Adenia volkensii belongs to section Blepharanthes. Several other species belonging to this section have medicinal properties.

Adenia ellenbeckii

Adenia ellenbeckii Harms occurs in Ethiopia, Somalia, Kenya, Uganda and Tanzania. A decoction of its fruit is taken to treat wounds and fruit powder is applied to the wounds. The juice of the fruit added to meat is used to poison hyenas. In Ethiopia the leaves are eaten as a vegetable.

Adenia keramanthus

Adenia keramanthus Harms occurs in Kenya and Tanzania. A stem extract is taken to treat syphilis and the leaves and roots are chewed to treat snakebites.

Adenia lanceolata

Adenia lanceolata Engl. occurs from southern Sudan to Malawi and is poisonous.

Adenia ellenbeckii, Adenia keramanthus and Adenia lanceolata contain cytotoxic lectins. The effect of the lectin from Adenia lanceolata is similar to the effect of volkensin on cell-free protein synthesis, but the former is more effective on whole cells, and is one of the most potent toxins of plant origin.

Growth and development

Adenia volkensii is fast growing and flowers more profusely if growing in direct sunlight. It has the ability to store water in the rootstock.


Adenia volkensii occurs in scrubby vegetation in rocky localities on red soil or lava-dust at 1000–2000 m altitude. It regenerates quickly after damage by cutting and from light fires.

Propagation and planting

Adenia volkensii can be propagated by seed and by stem cuttings. Cuttings taken from mature plants seem to flower more easily. The cuttings do not necessarily result in formation of a rootstock.


The stem, rootstock and leaves of Adenia volkensii are collected from the wild whenever needed and can be used fresh or dried.

Genetic resources

Adenia volkensii is fairly widespread in its distribution area and therefore not likely to be threatened by genetic erosion.


Adenia volkensii will remain important in East Africa both in human and in veterinary traditional medicine. The active ingredients of Adenia volkensii and related species, especially the ribosome-inactivating proteins, warrant further study. Large-scale cultivation for pharmaceutical products seems possible since other Adenia species are quite easily propagated for ornamental purposes.

Major references

  • Chambery, A., Di Maro, A., Monti, M.M., Stirpe, F. & Parente, A., 2004. Volkensin from Adenia volkensii Harms (kilyambiti plant), a type 2 ribosome-inactivating protein. European Journal of Biochemistry 271(1): 108–117.
  • de Wilde, W.J.J.O., 1971. A monograph of the genus Adenia Forsk. (Passifloraceae). Mededelingen Landbouwhogeschool Wageningen 71–18. Wageningen, Netherlands. 281 pp.
  • de Wilde, W.J.J.O., 1975. Passifloraceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 71 pp.
  • Fernandes, R. & Fernandes, A., 1978. Passifloraceae. In: Launert, E. (Editor). Flora Zambesiaca. Volume 4. Flora Zambesiaca Managing Committee, London, United Kingdom. pp. 368–411.
  • Gondwe, A.T.D., Seigler, D.S. & Dunn, J.E., 1978. Two cyanogenic glucosides, tetraphyllin B and epitetraphyllin B, from Adenia volkensii. Phytochemistry 17: 271–274.
  • Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

Other references

  • Barbiera, L., Falasca, A.L. & Stirpe, F., 1984. Volkensin, the toxin of Adenia volkensii (kilyambati plant). Febs Letters 171(2): 277–279.
  • Clausen, V., Wellendorph, P., Ekpe, P. & Jaroszewski, J.W., 2001. Tetraphyllin B, volkenin and cyclopentenylglycine in Androsiphonia adenostegia. Biochemical Systematics and Ecology 29(3): 317–319.
  • ITDG & IIRR, 1996. Ethnoveterinary medicine in Kenya. A field manual of traditional animal health care practice. Intermediate Technology Development Group and International Institute of Rural Reconstruction, Nairobi, Kenya. 226 pp.
  • Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp.
  • Kraft, C., Jenett-Siems, K., Siems, K., Jakupovic, J., Mavi, S., Bienzle, U. & Eich, E., 2003. In vitro antiplasmodial evaluation of medicinal plants from Zimbabwe. Phytotherapy Research 17(2): 123–128.
  • LaGrone, R.P., 1999. Method of treating humans with disease characterised by high secretion of cytokines from macrophage cells. [internet] 6407068.html. August 2006.
  • Morgan, W.T.W., 1981. Ethnobotany of the Turkana: use of plants by a pastoral people and their livestock in Kenya. Economic Botany 35(1): 96–130.
  • Pangalos, M.N., Francis, P.T., Pearson, R.C., Middlemiss, D.N. & Bowen, D.M., 1991. Destruction of a sub-population of cortical neurones by suicide transport of volkensin, a lectin from Adenia volkensii. Journal of Neuroscience Methods 40(1): 17–29.
  • Pelosi, E., Lubelli, C., Polito, L., Barbieri, L., Bolognesi, A. & Stirpe, F., 2005. Ribosome-inactivating proteins and other lectins from Adenia (Passifloraceae). Toxicon 46(6): 658–663.
  • Stirpe, F., Barbieri, L., Abbondanza, A., Falasca, A.I., Brown, A.N., Sandvig, K., Olsnes, S. & Pihl, A., 1985. Properties of volkensin, a toxic lectin from Adenia volkensii. Journal of Biological Chemistry 260(27): 14589–14595.
  • Szalai, K., Schöll, I., Förster-Waldl, E., Polito, L., Bolognesi, A., Untersmayr, E., Riemer, A.B., Boltz-Nitulescu, G., Stirpe, F. & Jensen-Jarolim, E., 2005. Occupational sensitization to ribosome-inactivating proteins in researchers. Clinical and Experimental Allergy 35(10): 1354–1360.

Sources of illustration

  • de Wilde, W.J.J.O., 1971. A monograph of the genus Adenia Forsk. (Passifloraceae). Mededelingen Landbouwhogeschool Wageningen 71–18. Wageningen, Netherlands. 281 pp.


  • D.M. Modise, University of South Africa, P.O. Box 392, Pretoria 0003, South Africa

Correct citation of this article

Modise, D.M., 2007. Adenia volkensii Harms. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 14 November 2020.